Why your ferritin will not move, and the protocol that shifts it.
Functional ferritin ranges, the five things blocking absorption, and the every-other-day dosing schedule that actually gets iron through.
01 of 06
Why ferritin matters more than you were told
Standard lab ranges flag ferritin as low only when it drops below 12. Some labs use 10. By that point your body has been iron-starved for months or years.
the range was built to catch anemia, not to tell you whether iron is working
Functional optimal for a woman is 70 to 100 ng/mL. Most women I see are between 10 and 30. Their doctor said it was normal. It is not.
Iron is a cofactor for thyroid peroxidase, the enzyme that produces thyroid hormone. Low iron means that enzyme cannot do its job no matter how much thyroid medication you take. Low ferritin also impairs T4 to T3 conversion, reduces how T3 binds to its receptor, drives mitochondrial energy collapse and destabilises mast cells.
If your ferritin is under 30 and you have fatigue, hair loss, cold hands and feet, brain fog, or thyroid medication that does not seem to work, this is the first thing to fix. Not the medication dose. The substrate underneath it.
02 of 06
Five reasons your ferritin will not go up
five gates, and the supplement only clears the last one
01 · Low stomach acid
Iron needs hydrochloric acid to convert into a form your gut can absorb. Hashimoto's and hypothyroid both reduce acid production, so you swallow iron your stomach cannot process. Bloating, reflux or feeling full quickly after meals points here.
02 · H. pylori
Helicobacter pylori lives in the stomach lining and directly suppresses iron absorption. If ferritin will not budge after months of supplementing, this belongs on the list to rule out. A stool test or breath test confirms it.
03 · Gut inflammation
Celiac, inflammatory bowel disease, SIBO or any active barrier problem damages the absorptive surface of the small intestine. The iron passes through without being picked up. You cannot supplement your way out of a broken pathway.
04 · Wrong timing
Coffee, tea or dairy within an hour. Iron taken alongside thyroid medication, which competes directly. Or daily dosing, when hepcidin stays elevated for 24 hours after a dose and the next one arrives against a closed gate.
05 · Heavy menstrual bleeding
If you lose iron faster than you absorb it, no supplement protocol fixes that math. Ferritin at 6 with heavy periods is a loss problem, and the bleed has to be addressed alongside the supplementation.
The one most people miss
Every other day dosing improved absorption 34 percent over daily dosing in the Stoffel 2017 study, because hepcidin spikes after a dose and stays up for a full day. Taking iron every morning is absorbing against a closed gate half the time.
03 of 06
The protocol
Primary route
What
Dose
Why this one
Iron bisglycinate
25 to 50 mg every other day
Chelated form. Gentler on the gut than ferrous sulfate and better absorbed. The every-other-day schedule keeps hepcidin low so the next dose gets through.
Vitamin C
500 mg with the iron dose
Converts non-heme iron into a form your gut absorbs more efficiently. Take them together every time.
If oral iron does not agree with you
What
Dose
Why this one
Lactoferrin
250 mg daily
If iron causes nausea, constipation or stomach pain, switch. Lactoferrin delivers iron through a different pathway with fewer gut side effects and carries its own anti-inflammatory and antimicrobial activity.
Pick one route
Lactoferrin is a replacement for oral iron, not an addition to it.
04 of 06
The timing that makes or breaks it
one day, four windows, in order
When
What
Wake up
Thyroid medication on an empty stomach with water. Nothing else.
30 to 60 min later
Breakfast. Coffee or tea if you want it. No iron yet.
4+ hours after thyroid med
Iron bisglycinate plus vitamin C, on an empty stomach or with meat. No coffee, tea, dairy or calcium within an hour either side.
The next day
No iron. Hepcidin is elevated. Skip, and take again the day after.
Every 8 to 12 weeks
Retest ferritin. It moves slowly. Be patient and consistent.
05 of 06
What blocks absorption
Coffee or tea within an hour. Tannins bind iron and prevent absorption.
Dairy or calcium at the same time. Calcium competes directly for uptake.
Thyroid medication too close. Levothyroxine and iron bind each other. Four hours apart minimum.
Daily dosing. Hepcidin spikes for 24 hours after each dose, so the next day the gate is shut.
Ferrous sulfate that causes gut distress. Switch to bisglycinate or lactoferrin. Compliance matters more than form.
06 of 06
When to retest
Ferritin moves slowly. Retest every 8 to 12 weeks and do not expect dramatic changes at four. Consistency across months is what builds the floor.
Once ferritin reaches 70 to 100 you can drop to a maintenance dose, every third day or two to three times a week, and retest quarterly. If you stop entirely and you menstruate, it will fall again. This is ongoing support rather than a phase.
If ferritin has not moved after 12 weeks of consistent supplementation with correct timing, investigate further. Rule out H. pylori, celiac or ongoing blood loss. The iron is not the problem. Something is blocking it or draining it.
Educational content
This is not medical advice. I share what I see on real panels to help you understand what your labs mean and ask better questions. Always work with a qualified healthcare provider for diagnosis and treatment.
Need a deeper look?
If your labs are complicated, your ferritin will not budge, or you want a full protocol built around your bloodwork, that is what 1:1 coaching is for.